Downdraft vent unit for a cooktop



FIG. 1 is a top perspective view of a modular downdraft vent unit for a cooktop showing my new design;

FIG. 2 is side elevational view thereof, the opposte side being a mirror image of that shown; and,

FIG. 3 is an end elevational view thereof, the opposite end being a mirror image of that shown.

The broken-line showing of a cooktop in FIGS. 1-3, is for illustrative purposes only, and forms no part of the claimed design. 

The ornamental design for a downdraft vent unit for a cooktop, as shown and described. 